A second night of looting and violence gripped the capital of Kyrgyzstan last night as the opposition, having declared leader Kurmanbek Bakiyev the new head of state, struggled to control the city after four people were killed in rioting earlier in the day.

The interior ministry said it was considering a curfew to restore order, as Mr Bakiyev appointed a new police chief, top prosecutor, and defence minister to try to restore order. Felix Kulov, a former vice-president and police chief released from prison on Thursday and now coordinating law enforcement, told the Associated Press: "It's an orgy going on here. We have arrested many people, we are trying to do something, but we physically lack people."

An Interfax report that the curfew was supposed to start at 6pm was later denied. At 7.15pm angry looters appeared to have broken into the TsUM department store, the only major shop not devastated in Thursday night's destruction. Police stood by as looters attacked civilians.

Yesterday Mr Bakiyev told crowds of supporters that since the flight of President Askar Akayev, the prime minister had taken on presidential powers under the constitution. Yet Mr Akayev remained defiant, saying in an online statement that the revolution was "an anti-constitutional coup".

"My current stay outside the country is temporary," Mr Akayev wrote. "Rumours of my resignation are deliberate, malicious lies."

The moves came as the Russian president, Vladimir Putin, expressed regret over Thursday's violence, but struck a conciliatory tone with the interim government. He describing them as people Moscow knew "pretty well" who "have done quite a lot to establish good relations between Russia and Kyrgyzstan" - the closest they have yet come to international recognition.

He appeared to sound the death knell of the Akayev administration by adding that the millionaire, who ruled the impoverished state for 15 years, would be welcome in Russia.

Yesterday, as he greeted fellow politicians inside the parliament building, Mr Bakiyev told the Guardian: "I have not heard from Mr Akayev at all. He is the one who discarded us, and if he had not, all this [situation] would not have happened."

About the looting, he said: "We do not want disorder, but some groups went wild and broke up shops and windows." Asked if he thought the situation could degenerate into civil war, he replied: "I don't think it will come to that."

Early yesterday drunk and angry crowds of young men tore apart the Plaza shopping centre, clashing inside with security and other protesters. Looters filled the streets of the capital, carrying bulging shopping bags or home microwaves, and cramming TVs and fridges into their cars.

Inside the Plaza, Antonina, an ethnic Russian who is in charge of a games machine there, sat slumped on a chair surrounded by bloody glass shards and crushed toys. "This new government have no idea what to do, and now we are left without food, work and pensions," she said. "They just wanted power."

The interim government struggled to appear coherent yesterday. Earlier, Ishenbai Kadyrbekov, appointed acting president by parliament on Thursday, told the Guardian: "The police are demoralised, terrified to go out on the street after yesterday. We must also be careful not to use [police] measures that could spark further popular violence."